Innovation in Metal Roofing: The Trap-Tee Panel's Advanced Design Features

A new metal roofing solution has emerged to tackle the challenges of large-scale industrial buildings with low-slope roofs. The Trap-Tee panel, developed by McElroy Metal's National Recover Manager, Charlie Smith, represents a significant advancement in metal roofing technology, particularly for projects requiring long panel runs and enhanced structural performance requirements.

Evolution of Design

The Trap-Tee panel builds upon the success of previous symmetrical panel designs, including the 138T and 238T panels. Smith explains, "The 238T is designed to go on a solid deck, or it can be installed on open purlins". However, limitations with these earlier designs, especially for low-slope applications, prompted the development of the Trap-Tee.

Smith notes, "The 2⅜ inch height of 238T has been restrictive for really long runs on lower slopes". He highlights that lengths of 150-200 feet or more on a quarter-on-12 slope have posed challenges for issuing a weather-tight warranty. This struggle was a key factor driving the new design and, ultimately, why we wanted to use a 2 ¾ inch panel height for the Trap-Tee product.

Key Innovations

Beyond the additional height of the vertical leg, the Trap-Tee incorporates several significant design improvements to enhance its functionality and performance:

• Enhanced Seam Design: The Trap-Tee panel features a wider seam of 1½ inches, compared to the 1-inch wide seam cap for 238T & 138T.
• Bigger Clips: Trap-Tee accommodates larger 16-gauge clips to provide even greater wind uplift.
• Multiple Clip Options: According to Smith, "The normal clip for the Trap-Tee is 8 inches long, and the super clip is 16 inches long". These clip options provide significantly increased wind uplift and snow load capacity. Additionally, they offer improved performance on open purlins and are more installer-friendly.
• Individual panel replaceability: Thanks to the symmetrical panel design, the Trap-Tee panel offers individual panel replaceability in the field of the roof. In fact, thanks to the use of an unseaming machine, the original panel can often be reused, requiring only the purchase of a new batten cap.
• High wind uplift & superior snow load: Between the wide batten cap and clip design, the Trap-Tee panel delivers unparalleled wind and snow loads.

Structural Benefits

The super clip system offers remarkable structural advantages. Smith explains, "If you're working with a 5' on center purlin spacing, using the super clip gives you the same basic gravity load as the purlins being at 3 foot 6 inches. That's a huge deal."

Long-Run Capability

One of the most significant advantages of the Trap-Tee system is its ability to accommodate extremely long runs without seams. Smith states, "The panels can be manufactured right onto the roof in continuous lengths, and the longest panels that we've run at 250' plus. This capability addresses a common issue with traditional systems, as panel endlaps are the single most common areas for roof leaks. We can also produce this profile in our manufacturing facilities for smaller projects or shorter panel runs."

To learn more, download our Trap-Tee flyer and Recover Infographic.